Gasket for screen frame

ABSTRACT

A screen assembly for a vibrating shaker is provided. The screen assembly utilizes an elastomeric gasket having a flat profile section and a bulb profile section, wherein said bulb profile section has a hollow interior and is configured so as to form a notched profile section where said bulb profile section connects to said flat profile section.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.62/538,248 filed Jul. 28, 2017 titled “Gasket for Screen Frame,” whichis hereby incorporated by reference.

FIELD

The present disclosure relates generally to a vibrating screen assemblyused in vibrating screen machines for screening or separating purposes.More specifically, the disclosure relates to gaskets used as a sealbetween the screen frame and the deck of the vibrating screen machines.

BACKGROUND

Vibrating screen machines (often referred to as shakers) utilize ascreen assembly or a plurality of screen assemblies to separate solidmaterial from liquids and fine solid particles. The screen assembly istypically secured in and to the vibrating machinery through use of aframe. In some cases, a single screen assembly will be utilized while inother cases, a plurality of screen assemblies will be aligned adjacentto each other end-to-end. The screen assembly is removably attached tothe shaker. A mixture of materials is delivered or fed to the top of thescreen assembly. A motor at a high frequency vibrates the screenassembly.

The force of gravity plus the vibration of the screen assembly separatesthe liquid from particles larger than the pore size, which is made up bythe combination of layers. This pore size is called the “cut point.” Thescreen assembly may be inclined when secured in the vibrating shaker sothat the solids larger than the cut point will move across the screenwhere they are gathered and disposed of. The liquid and particlessmaller than the cut point pass through the screen assembly and can becollected also.

There are various types of screen assemblies having various frames. Inone configuration, a plurality of screen cloth layers is attached to aperforated plate which is, in turn, connected to the frame. Theperforated plate has a large number of small openings to minimize theunsupported spans of screen cloth. It is important to achieve goodadhesion between the perforated plate and the frame. Thus, the framemust have an adequate planar surface to attach securely to theperforated plate.

In some vibrating shakers, a bed or deck is composed of a plurality ofparallel, cushioned rails or gaskets on which the screen assembly orscreen assemblies rest. Use of such gaskets, which are adhered to thedeck, can be problematic because it can be very time consuming anddifficult to change the gaskets when they wear out. Accordingly, suchgaskets typically are not changed as often as they should.

In other vibrating shaker designs, the gasket is attached to the screenassembly instead of the bed or deck. In these instances, the gasket ischanged whenever the screen is changed since the two represent a singleintegrated item. In the past, it has been difficult for one gasket toprovide both an adequate seal and transmit vibrational energy to thescreen assembly. Typically, a design has either not sealed adequately orhas acted to dampen the transmitted vibrational energy. In eithercircumstance, performance of the shaker is hampered.

SUMMARY

In one embodiment there is provided a screen assembly for a vibratingshaker, which comprises a frame, a perforated plate, at least one screencloth, and an elastomeric gasket. The frame has a top side and anunderside. The perforated plate is affixed to the top side of the frame.The screen cloth is affixed to the top side of the frame above theperforated plate. The elastomeric gasket has a flat profile sectionconnected to a compressible section, wherein the flat profile sectionprovides for rigid mount of the frame on the vibrating shaker so as toallow transmission of vibrational energy, and wherein the compressiblesection is more compressible than the flat profile section so as toprovide a fluid tight seal. In some embodiments, the compressiblesection is comprised of foam rubber. In other embodiments, thecompressible section is a bulb profile section.

The bulb profile section has a hollow interior and is configured so asto form a notched profile section where the bulb profile sectionconnects to the flat profile section. In many of these embodiments, theelastomeric gasket has a first surface and a second surface wherein thefirst surface and second surface oppose each other. The cross-sectionalprofile is configured such that the first surface is flat and the secondsurface is configured to provide the flat profile section, the bulbprofile section and the notch profile section. The flat profile sectionhas a first height and the bulb section an apex height. Generally, theapex height can be at least 10 percent greater than the first height.The notched profile section has a nadir height. Typically, the nadirheight is at least 10 percent less than the first height.

The elastomeric gasket can have a first edge and a second edge, with thefirst edge opposing the second edge, and with both the first edge andsecond edge extending from the first surface to the second surface. Inone set of embodiments, the bulb profile section is adjacent the firstedge, and the flat profile section extends from the notched profilesection to the second edge. In another set of embodiments, the flatprofile section comprises a first flat profile section and a second flatprofile section, and the notched profile section comprising a firstnotched profile section and a second notched profile section. The firstnotched profile section is on a first side of the bulb profile sectionand the second notched profile section is on a second side of the bulbprofile section. The first flat profile section extends from the firstedge to the first notched profile section, and the second flat profilesection extends from the second edge to the second notched profilesection.

In many embodiments, the second surface of the elastomeric gasket restson the vibrating shaker and the first surface of the elastomeric gasketis attached to the underside of the frame.

In many embodiments, the elastomeric gasket is compressible andresilient. The elastomeric gasket can be extruded. Alternatively, theelastomeric gasket can be molded.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, perspective view of a vibrating assembly inaccordance with one embodiment.

FIG. 2 is a bottom view of the frame with a perforated plate and sealinggasket in accordance with one embodiment.

FIG. 3 is a bottom view of a gasket in accordance with the embodiment ofFIG. 2.

FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 2.

FIG. 5 is an enlarged cross-sectional view of the gasket taken alongline 5-5 of FIG. 3.

FIG. 6 is a bottom view of the frame with a perforated plate and sealinggasket in accordance with a second embodiment.

FIG. 7 is an explosive view of area 7 from FIG. 6.

FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 6.

FIG. 9 is a schematic cross-sectional illustration of an alternativeembodiment.

DETAILED DESCRIPTION

In the description that follows, like parts are marked throughout thespecification and drawings with the same reference numerals,respectively. The drawings are not necessarily to scale and theproportions of certain parts have been exaggerated to better illustratedetails and features of the invention. Where components of relativelywell-known designs are employed, their structure and operation will notbe described in detail.

Referring to the drawings in detail, FIG. 1 illustrates an exploded,perspective view of one preferred embodiment of a vibrating screenassembly 10 constructed in accordance with the present invention. Aframe 12 includes a pair of parallel, opposed sides 14 and 16 and a pairof opposed, parallel ends 18 and 20. Generally, sides (14 and 16) andends (18 and 20) are composed of steel or aluminum, although it shouldbe understood that other materials, such as composites, might also beused.

Frame 12 includes an underside 22 and an opposed top side 24. Top side24 of frame 12 has a flat, planar surface. A perforated plate 30 isattached to and secured to the frame 12 in the assembled condition.Perforated plate 30 includes a plurality of openings 31 which arepunched or otherwise formed in the plate 30. Perforated plate 30 mayinclude a border area which will align with the planar surfaces of thetop side of the frame, providing an area for good adhesion between theframe and the plate.

At least one screen cloth 32 is secured to perforated plate 30. Screenassembly 10 can be made of a single woven wire screen layer or ofmultiple screen layers.

Frame 12 also includes a plurality of tubular cross supports 34 whichextend between the sides 14 and 16. The tubular cross supports may befabricated from the same or different material as the sides and ends offrame 12.

A gasket 40 is attached to underside 22 of frame 12, as better seen fromFIGS. 2, 3 and 4. FIG. 2 illustrates a bottom view of frame 12 withperforated plate 30 and gasket 40 attached. The bottom view of thegasket shown with more detail is illustrated in FIG. 3. FIG. 4illustrates a cross-sectional view of FIG. 2 along line 4-4. Gasket 40can be attached to frame 12 by any suitable means such as by directlymolding the gasket onto the screen frame or by attaching the gasket byan adhesive, as is known in the art such as for attaching rubber-typecompounds to metal or composites. Alternatively, gasket 40 can beattached by fasteners or by other suitable mechanical means, such asinsertion of a rail portion of gasket 40 into a slot in frame 12.

Gasket 40 is a sealing gasket and typically is elastomeric. Preferably,gasket 40 is both compressible and resilient. Gasket 40 may be made fromany suitable material, for example gasket 40 can be extruded or moldedfrom neoprene, nitrile rubber (Buna N), fluroelastomers (such as soldunder the trademark Viton) or other similar materials and then cut intodesired lengths, as best seen in FIG. 1. It may be necessary to miterthe ends of the gasket 40 to match the frame or alternatively, the endsof the gaskets can be sealed together. Generally, gasket 40 isconfigured to run around the perimeter of underside 22 of frame 12, asillustrated in FIGS. 2 and 4. As illustrated in FIG. 1, gasket 40 isfour pieces or segments installed onto frame 12; however, moretypically, the ends of each segment are mitered and joined in a fluidtight seal to one of the other gasket ends (such as by vulcanization) toform one continuous closed gasket prior to installation on frame 12.

FIGS. 4 and 5 show the cross-sectional shape of gasket 40 for oneembodiment. As shown, gasket 40 has a first or upper surface 42 which isflat and constructed to rest on the underside 22 of frame 12. Underside22 is typically a flat, planar surface. Generally, upper surface 42being flat makes it suitable for attachment to frame 12 by adhesive.However, where the attachment is by mechanical means, such as a rail andslot arrangement, upper surface 42 can have another suitable shape.

In the embodiment illustrated in FIGS. 4 and 5, gasket 40 has a secondor lower surface 44, which is configured to rest on the bed or rail of avibrating shaker (not shown) in such a manner as to make a sealingengagement with the bed or rail but not to dampen transmission ofvibrational energy, or at least to reduce the dampening effects of thesealing gasket. Accordingly, lower surface 44 has a flat profile section(shown as two flat profile sections 46 a and 46 b but which could bejust one of flat profile sections 46 a or 46 b) connected to acompressible section, which is illustrated as a bulb profile section 48.Additionally, bulb profile section 48 has a hollow interior 50 and isconfigured so as to form a notched profile section 52 where bulb profilesection 48 connects to the flat profile section 46 a and/or 46 b. Theflat profile section, bulb profile section and notched profile section,all run longitudinally along the length of each segment of gasket 40such that they run around the perimeter of frame 12 when gasket 40 isinstalled on frame 12.

Flat profile section 46 a and/or 46 b has a flat, planar surface 54 suchthat frame 12 has a rigid mount to allow the transmission of vibrationalenergy with minimal dampening. Flat profile section 46 a and/or 46 balso prevents the over compression of bulb profile section 48 of theseal. Typically, the compressible section (for example, bulb profilesection 48) is more compressible than flat profile section 46 a and/or46 b so that the compressible section provides a fluid tight seal whilethe flat profile section allows the better transmission of vibrationalenergy than the compressible section.

Bulb profile section 48 extends outward past surface 54 of flat profilesection 46 a and/or 46 b so that bulb profile section 48 contacts thebed or rail of a vibrational shaker prior to flat profile section 46 aand/or 46 b contacting the bed or rail. Additionally, bulb profilesection 48 has hollow interior 50 such that it can easily compress;thus, the height and hollow interior 50 allow bulb profile section 48 tocreate a fluid tight seal with the bed or rail of the vibrationalshaker. Notched profile section (shown as two notched profile sections52 a and 52 b but which could be just one of notched profile section)provides an area for lateral expansion of bulb profile section 48 as itundergoes longitudinal compression when contacting and forming a sealwith the bed or rail of a vibrational shaker.

In some embodiments, flat profile section 46 a and/or 46 b has a firstheight 56 and bulb profile section 48 has an apex height 58. The apexheight is measured from the outermost portion of the bulb. Generally,the apex height can be at least 5 percent, at least 10 percent or atleast 20 percent greater than the first height. Generally, the apexheight will be no more than 50 percent, no more than 45 percent or nomore than 30 percent greater than the first height. In some embodiments,the apex height is from 30 percent to 35 percent greater than the firstheight. As shown in FIG. 5, the apex height is about 33 percent greaterthan the first height.

The notched profile section can be round, such as a semicircular shape,or have an angular V-shape. In either configuration, the notched profilesection has a nadir height 59, measured from upper surface 42 to notchedprofile sections innermost point from planar surface 54. Typically, thenadir height is at least 5 percent less, at least 10 percent less or atleast 20 percent less than the first height. In some embodiments, thenadir height is no less than 60 percent less, 55 percent less or 50percent less than the first height. In some embodiments, the nadirheight is from 40 percent to 50 percent of the first height, as shown inFIG. 5.

In one embodiment illustrated in FIGS. 4 and 5, the bulb profile sectionis positioned between two flat profile sections with a notched sectionon each side. For such embodiments, the two flat profile sections cantypically be the same size, and the two-notched sections can typicallybe the same size. Thus, the bulb profile section will run longitudinallyalong the center of the gasket. However, it is within the scope of theinvention for the bulb profile section to run longitudinally and becloser to or adjacent an edge of the gasket. Also, it is within thescope of the invention for there to be two or more bulb profile sectionsrunning longitudinally along the gasket.

For example, in the embodiment illustrated in FIGS. 2, 3, 4 and 5,gasket 40 has a first edge 60 and a second edge 62, with first edge 60opposing second edge 62, and with both first edge 60 and second edge 62extending from upper surface 42 to lower surface 44. There are two flatprofile sections, a first flat profile section 46 a and a second flatprofile section 46 b. Also, there are two notched profile sections, afirst notched profile section 52 a and a second notched profile section52 b. First notched profile section 52 a is on a first side 64 of bulbprofile section 48 and the second notched profile section 52 b is on asecond side 66 of bulb profile section 48. First flat profile section 46a extends from first edge 60 to first notched profile section 52 a, andsecond flat profile section 46 b extends from second edge 62 to secondnotched profile section 52 b. Further, as illustrated, first and secondflat profile sections 46 a and 46 b have equal widths, and first andsecond notched profile sections 52 a and 52 b have equal widths.

In another embodiment illustrated in FIGS. 6, 7 and 8, the bulb profilesection 48 is located at an inner edge 70 of the border of frame 12,which is made of sides 14 and 16 and ends 18 and 20. For example, insome vibratory shakers, a notch or hole 68 is needed to allow for a deckpin (a retaining pin). In such embodiments, having the bulb profilesection intersecting with the notch would prevent a liquid tight sealfrom being obtained at notch 68. However, the rigid mounting provided bythe flat profile surface is not adversely affected by notch 68.Accordingly, bulb profile section 48 is positioned so as to runlongitudinally adjacent first edge 60 of gasket 40, which is alignedwith inner edge 70 and can be adjacent inner edge 70. Flat profilesection extends from notched profile section 52 to second edge 62, whichtypically is adjacent to an outer edge of frame 12. As illustrated inFIGS. 7 and 8, flat profile section comprises a first flat profilesection 46 a and a second flat profile section 46 b with a notch profilesection 47 joining the two flat profile sections 46 a and 46 b.Alternatively, flat profile section can be a single flat profile sectionextending from notched profile section 52 to second edge 62 without anynotch in the single flat profile section. Thus, it is within the scopeof the invention for the flat profile section of the embodiments to beone continuous profile section or divide into two, three or more flatprofile sections separated by notched profile sections.

The width of the gasket 40 (from first edge 60 to second edge 62) canhave a total flat profile section width sufficient to provide a rigidmount to allow the transmission of vibrational energy. Additionally, thetotal width of bulb profile section 48, include the notched profilesection 52, can be sufficient to make a liquid tight seal between frame12 and the vibrational shaker. Generally, the width of the flat profilesection can be from about 50% to about 90% of the total width of gasket40, and more typically, the width of the flat profile section can befrom 60% to 85% or from 65% to 80% of the total width of gasket 40.Generally, the total width of bulb profile section 48 (including notchedprofile section 52) can be from about 10% to about 50% of the totalwidth of gasket 40, and more typically from 15% to 40% or from 20% to35% of the total width of gasket 40. Notched profile section 52 cangenerally be up to 70% of the width of the bulb profile section 48, butmore typically, can be up to about 50% of the width of the bulb profilesection 48. Generally, if used, notch profile section 52 can be at leastabout 10%, or at least about 20%, or at least 25% of the width of bulbprofile section 48.

In the alternative embodiment illustrated in FIG. 9, gasket 40 comprisesa foam rubber segment 72, which replaces the bulb profile section, inmany embodiments both the bulb section and notched segment adjacent thebulb section are replaced with foam rubber segment 72. In thisembodiment, there is a flat profile segment 74 which is adjacent to andcan be attached to or integral with foam rubber segment 72. Typically,foam rubber segment 72 will be adjacent inner edge 70 but can becentered between two flat profile segments, or flat profile segment 74can be adjacent inner edge 70 and foam rubber segment 72 can be betweenflat profile segment 74 and the outer edge of frame 12.

When foam rubber segment 72 is used, its height can be at least 5percent, at least 10 percent or at least 20 percent greater than thefirst height of flat profile segment 74. Generally, the height will beno more than 100 percent, no more than 50 percent or no more than 30percent greater than the first height. In some embodiments, the heightis from 30 percent to 35 percent greater than the first height.

Generally, the width of flat profile segment 74 can be from about 50% toabout 90% of the total width of gasket 40, and more typically, the widthof flat profile segment 74 can be from 60% to 85% or from 65% to 80% ofthe total width of gasket 40. Generally, the total width of foam rubbersegment 72 (including a notched profile section, if any) can be fromabout 10% to about 50% of the total width of gasket 40, and moretypically from 15% to 40% or from 20% to 35% of the total width ofgasket 40.

Foam rubber segment 72 can be made from any suitable foam rubber-typecompound, such as foam neoprene, foam nitrile rubber, foamfluroelastomers or other materials.

Although the invention has been described with reference to a specificembodiment, the foregoing description is not intended to be construed ina limiting sense. Various modifications as well as alternativeapplications will be suggested to persons skilled in the art by theforegoing specification and illustrations. It is therefore contemplatedthat the appended claims will cover any such modifications, applicationsor embodiments as followed in the true scope of this invention.

What is claimed is:
 1. A screen assembly for a vibrating shaker, whichcomprises: a frame having a top side and an underside; a perforatedplate affixed to said top side of said frame; at least one screen clothaffixed to said top side of said frame above said perforated plate; andan elastomeric gasket having a flat profile section connected to acompressible section, wherein the flat profile section provides forrigid mount of the frame on the vibrating shaker so as to allowtransmission of vibrational energy, and wherein the compressible sectionis more compressible than the flat profile section so as to provide afluid tight seal.
 2. The screen assembly according to claim 1, whereinthe compressible section is comprised of foam rubber.
 3. The screenassembly according to claim 1, wherein the compressible section is abulb profile section, wherein said bulb profile section has a hollowinterior and is configured so as to form a notched profile section wheresaid bulb profile section connects to said flat profile section.
 4. Thescreen assembly according to claim 1, wherein said elastomeric gasket iscompressible and resilient.
 5. The screen assembly according to claim 1,wherein said elastomeric gasket is extruded.
 6. The screen assemblyaccording to claim 1, wherein said elastomeric gasket is molded.
 7. Thescreen assembly according to claim 3, wherein said elastomeric gaskethas a first surface and a second surface, and wherein saidcross-sectional profile is configured such that said first surface isflat and said second surface is configured to provide said flat profilesection, said bulb profile section and said notch profile section. 8.The screen assembly according to claim 7, wherein said flat profilesection has a first height and said bulb section an apex height which isat least 10 percent greater than said first height.
 9. The screenassembly according to claim 7, wherein said notched profile section hasa nadir height which is at least 10 percent less than said first height.10. The screen assembly of claim 9, wherein said elastomeric gasket hasa first edge and a second edge, with said first edge opposing saidsecond edge, and with both said first edge and second edge extendingfrom said first surface to said second surface, and wherein said bulbprofile section is adjacent said first edge, and said flat profilesection extends from said notched profile section to said second edge.11. The screen assembly of claim 9, wherein said elastomeric gasket hasa first edge and a second edge, with said first edge opposing saidsecond edge, and with both said first edge and second edge extendingfrom said first surface to said second surface, and wherein said flatprofile section comprises a first flat profile section and a second flatprofile section, and said notched profile section comprising a firstnotched profile section and a second notched profile section such thatsaid first notched profile section is on a first side of said bulbprofile section, said second notched profile section is on a second sideof said bulb profile section, said first flat profile section extendsfrom said first edge to said first notched profile section, and saidsecond flat profile section extends from said second edge to said secondnotched profile section.
 12. The screen assembly of claim 11, whereinsaid second surface of said elastomeric gasket rests on said vibratingshaker and said first surface of said elastomeric gasket is attached tosaid underside of said frame.